Grounds maintenance vehicle with adjustable suspension system

ABSTRACT

Suspension systems and grounds maintenance vehicles incorporating the same are disclosed. The suspension system may include biasing elements or springs that may be adjusted to vary the preload and thus change the spring and dampening characteristics of the suspension system. In some embodiments, the system may include an adjustment mechanism that permits simultaneous adjustment of two springs via a single action. In other embodiments, features adapted to assist an operator with mounting/dismounting the vehicle are disclosed.

This application is a continuation application of U.S. patentapplication Ser. No. 17/095,453, filed Nov. 11, 2020, which is acontinuation application of U.S. patent application Ser. No. 16/157,506,filed Oct. 11, 2018, now U.S. Pat. No. 10,864,832, issued Dec. 15, 2020,which claims the benefit of U.S. Provisional Pat. App. No. 62/572,814,filed Oct. 16, 2017, the disclosures of which are incorporated herein byreference in their entireties.

Embodiments of the present disclosure are directed generally to ridinggrounds maintenance vehicles (e.g., turf care vehicles such as lawnmowers) having an adjustable suspension system, and, in otherembodiments, vehicle access features to assist with mounting anddismounting the vehicle.

BACKGROUND

Operators of grounds maintenance vehicles, such as zero-turn-radius(ZTR) mowers, often operate the vehicle for extended periods of time.Accordingly, mowers incorporating some type of suspension system havebecome more common in recent years. However, there may be significantvariability in what operators consider desirable with regard to specificsuspension system characteristics (e.g., stiffness/spring rate anddampening). Further, even the same operator may wish to adjust thesecharacteristics over time (or even over the course of a single workday).

While configurations vary, some known suspension systems are complex andill-suited to providing the variability in spring rate and/or dampeningcharacteristics needed to satisfy a wide range of operators and terraintypes. Moreover, some of these suspension systems are complicated, whichmay not only increase the cost of manufacture, but may requirecorrespondingly complicated repairs and/or maintenance.

In addition to ride comfort, convenient access to the mower's operatorplatform (e.g., seat) is also desirable. Typically, to reach theoperator seat, the operator first steps onto the mower's floor pan orfoot area, which is generally located immediately forward of the seat.The foot area is usually accessed via the side or the front of themower.

When the mower has one or more large cutting decks (or other side orfront attachments), mounting the mower may present challenges for someoperators (e.g., those of shorter stature and/or those having certainphysical limitations). For example, for mowers having relatively widecutting decks, the operator may be required (when mounting from theside) to extend his or her leg across a relatively large distance inorder to step over the cutting deck (if the deck is not suited tobearing the operator's weight).

In other mowers, various components (e.g., out-front cutting decks) maybe located at or near the front end of the mower or, as is common withZTR mowers, the front of the mower may include a continuous, transverse,and upwardly angled foot rest. Such a configuration may also presentchallenges for some operators when mounting/dismounting the mower fromthe front. Due to their unique configuration, ZTR mowers may also lackgrab handles or similar structure that may be used by the operatorduring mounting/dismounting of the mower.

SUMMARY

Embodiments described herein may provide a grounds maintenance vehicleincluding: a chassis having a front end, a rear end, and a longitudinalaxis extending between the front and rear ends; a support platformextending along the longitudinal axis, wherein the support platformincludes a seat support portion; and a suspension system. The suspensionsystem includes a first suspension apparatus operatively acting betweenthe chassis and the seat support portion of the support platform. Thefirst suspension apparatus has first and second torsion springs, whereinthe torsion springs are adapted to elastically deflect when the supportplatform is displaced relative to the chassis. The suspension systemfurther includes: a second suspension apparatus longitudinallyspaced-apart from the torsion springs, wherein the second suspensionapparatus is operatively connected to both the support platform and thechassis; and an adjuster adapted to simultaneously adjust a preloadapplied to both of the first and second torsion springs.

In another embodiment, a grounds maintenance vehicle is provided thatincludes: a chassis having a front end, a rear end, and a longitudinalaxis extending between the front and rear ends. The vehicle alsoincludes a support platform extending along the longitudinal axis,wherein the support platform has a seat support portion, a foot supportportion, and a connecting structure connecting the seat support portionto the foot support portion. Moreover, the vehicle includes a suspensionsystem having a first suspension apparatus adapted to bias the supportplatform away from the chassis. The first suspension apparatus includesfirst and second torsion springs spaced-apart from one another in adirection transverse to the longitudinal axis, wherein the torsionsprings are adapted to elastically deflect when the support platform isdisplaced toward the chassis. The suspension system also includes: asecond suspension apparatus longitudinally spaced-apart from the firstsuspension apparatus, wherein the second suspension apparatus is alsoadapted to bias the support platform away from the chassis; and anadjuster adapted to simultaneously alter a preload applied to both ofthe first and second torsion springs.

In yet another embodiment, a riding lawn mower is provided thatincludes: a chassis having a front end, a rear end, and a longitudinalaxis extending between the front and rear ends; and a support platformextending along the longitudinal axis. The support platform includes: aseat support portion supporting an operator seat; a foot supportportion; and a connecting structure connecting the seat support portionto the foot support portion. The mower also includes a pivot memberdefining a transverse first pivot axis and a transverse second pivotaxis, wherein the pivot member is: pivotally coupled to the chassis atthe first pivot axis; and pivotally coupled to the support platform atthe second pivot axis. A suspension system is also provided and includesfirst and second torsion springs positioned about the second pivot axis.The torsion springs operatively bias the support platform upwardly andaway from the chassis and elastically deflect when the support platformis displaced toward the chassis. The torsion springs are locatedlongitudinally near the seat support portion. The suspension system alsoincludes: a coil-over shock absorber positioned longitudinally forwardfrom the first and second torsion springs, wherein the shock absorber isoperatively connected to the platform and to the chassis; and anadjuster adapted to simultaneously alter a preload applied to both ofthe first and second torsion springs.

The above summary is not intended to describe each embodiment or everyimplementation. Rather, a more complete understanding of illustrativeembodiments will become apparent and appreciated by reference to thefollowing Detailed Description of Exemplary Embodiments and claims inview of the accompanying figures of the drawing.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

Exemplary embodiments will be further described with reference to thefigures of the drawing, wherein:

FIG. 1 illustrates a grounds maintenance vehicle, e.g., riding lawnmower, incorporating an adjustable suspension system in accordance withembodiments of the present disclosure;

FIG. 2 is a partial perspective view of the mower of FIG. 1 illustratingportions of the exemplary suspension system;

FIG. 3 is another partial perspective view of the mower of FIG. 1 withcomponents (e.g., the seat and seat frame) shown exploded from aplatform of the mower;

FIG. 4 is a view similar to FIG. 2 , but with a support platform removedto better illustrate aspects of the exemplary suspension system;

FIG. 5 is an enlarged partial perspective view of a portion (e.g., firstsuspension apparatus) of the suspension system of FIGS. 1-4 ;

FIG. 6 is a torsion spring that forms an exemplary biasing element ofthe first suspension apparatus;

FIG. 7 is a section view taken along line 7-7 of FIG. 5 illustrating thesuspension system when the support platform is unloaded and a preloadadjustment mechanism of the system is set for a minimal (“least-stiff”)preload of the biasing elements;

FIG. 8 is a bottom perspective view of portions of an exemplarysuspension system in isolation;

FIG. 9 is a side elevation view of a lever-operated preload adjustmentmechanism in accordance with embodiments of the present disclosure, thepreload adjustment mechanism adapted to alter the preload of biasingelements of the suspension system;

FIG. 10 is a section view similar to FIG. 7 (i.e., the support platformshown unloaded), but with the preload adjustment mechanism set toprovide an intermediate preload to the biasing elements;

FIG. 11 is a partial perspective view of a preload adjustment mechanismin accordance with another embodiment of the present disclosure, themechanism including a two-step adjustment procedure;

FIG. 12 is bottom perspective view of the preload adjustment mechanismof FIG. 11 ;

FIG. 13 is section view taken along line 13-13 of FIG. 11 showing alever lock in a closed position;

FIG. 14 is a section view similar to FIG. 13 , but illustrating thelever lock in an open position;

FIG. 15 is a partial perspective view of a suspension system inaccordance with another embodiment of the present disclosure, whereinthe preload adjustment mechanism includes a threaded screw;

FIG. 16 is another perspective view of the suspension system of FIG. 15;

FIG. 17 is a section view taken along line 17-17 of FIG. 16 illustratingthe suspension system when the support platform is unloaded and thepreload adjustment mechanism is set for a minimal preload of the biasingelements;

FIG. 18 is a perspective view of the section shown in FIG. 17 ;

FIG. 19 is a section view similar to FIG. 17 , but shown with thesupport platform loaded;

FIG. 20 is a section view similar to FIG. 17 (i.e., the support platformshown unloaded), but with the preload adjustment mechanism set toprovide an intermediate preload to the biasing elements;

FIG. 21 is a partial, perspective section view of a suspension system inaccordance with another embodiment of the present disclosure, whereinthe first suspension apparatus is configured as a single coil-over shockabsorber;

FIG. 22 is a direct section view of the suspension system of FIG. 21 ;

FIG. 23 is a partial perspective view of mount/dismount assist bar inaccordance with embodiments of the present disclosure;

FIG. 24 is a side elevation view of the assist bar of FIG. 23 in both adeployed position (solid lines) and a stowed position (broken lines);

FIG. 25 is a perspective view of a grounds maintenance vehicle (e.g.,riding lawn mower) in accordance with another embodiment of the presentdisclosure, the mower shown incorporating low, step-through frontaccess; and

FIG. 26 is a partial, isolated view of a chassis of the mower of FIG. 25.

The figures are rendered primarily for clarity and, as a result, are notnecessarily drawn to scale. Moreover, various structure/components,including but not limited to fasteners, electrical components (wiring,cables, etc.), and the like, may be shown diagrammatically or removedfrom some or all of the views to better illustrate aspects of thedepicted embodiments, or where inclusion of such structure/components isnot necessary to an understanding of the various exemplary embodimentsdescribed herein. The lack of illustration/description of suchstructure/components in a particular figure is, however, not to beinterpreted as limiting the scope of the various embodiments in any way.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments,reference is made to the accompanying figures of the drawing which forma part hereof. It is to be understood that other embodiments, which maynot be described and/or illustrated herein, are certainly contemplated.

All headings provided herein are for the convenience of the reader andshould not be used to limit the meaning of any text that follows theheading, unless so specified. Moreover, unless otherwise indicated, allnumbers expressing quantities, and all terms expressingdirection/orientation (e.g., vertical, horizontal, parallel,perpendicular, etc.) in the specification and claims are to beunderstood as being modified in all instances by the term “about.” Theterm “and/or” (if used) means one or all of the listed elements or acombination of any two or more of the listed elements. “I.e.” is used asan abbreviation for the Latin phrase id est, and means “that is.” “E.g.”is used as an abbreviation for the Latin phrase exempli gratia, andmeans “for example.”

It is noted that the terms “comprises” and variations thereof do nothave a limiting meaning where these terms appear in the accompanyingdescription and claims. Further, “a,” “an,” “the,” “at least one,” and“one or more” are used interchangeably herein. Moreover, relative termssuch as “left,” “right,” “front,” “fore,” “forward,” “rear,” “aft,”“rearward,” “top,” “bottom,” “side,” “upper,” “lower,” “above,” “below,”“horizontal,” “vertical,” and the like may be used herein and, if so,are from the perspective of one operating the vehicle (e.g., mower 100of FIG. 1 ) while it is in an operating configuration, e.g., while themower 100 is positioned such that wheels 106 and 108 rest upon agenerally horizontal ground surface 105. These terms are used only tosimplify the description, however, and not to limit the interpretationof any embodiment described.

Still further, the suffixes “a” and “b” may be used throughout thisdescription to denote various left- and right-side parts/features,respectively. However, in most pertinent respects, the parts/featuresdenoted with “a” and “b” suffixes are substantially identical to, ormirror images of, one another. It is understood that, unless otherwisenoted, the description of an individual part/feature (e.g., part/featureidentified with an “a” suffix) also applies to the opposing part/feature(e.g., part/feature identified with a “b” suffix). Similarly, thedescription of a part/feature identified with no suffix may apply,unless noted otherwise, to both the corresponding left and rightpart/feature.

While various embodiments are possible within the scope of thisdisclosure, some embodiments are directed to grounds maintenancevehicles that include a chassis supported by one or more ground contactmembers. The vehicle also includes an operator support platform adaptedto support a riding operator, and a suspension system operatively actingbetween the chassis and the support platform. The suspension system mayattenuate forces, e.g., travel-induced forces, which may otherwise betransmitted to the support platform during vehicle operation. Statedanother way, the support platform, and thus the operator, may bepartially isolated from forces imparted to the chassis as a result ofvehicle operation. Moreover, in some embodiments, the suspension systemmay permit adjustment of spring rate and/or dampening of the suspensionsystem to, for example, better accommodate a range of operator ridingpreferences. Some embodiments may provide a single adjuster that altersthe spring rate and/or dampening characteristics of multiple suspensionsunits simultaneously. Such a configuration may be beneficial when, forexample, symmetric adjustment of multiple suspension units is desired.

Still further, illustrative suspension systems may provide a lowprofile, permitting components of the suspension system (e.g., thesuspension units) to be contained within an envelope generally definedby the remainder of the vehicle.

In other embodiments, operator assistance features may be provided toassist with mounting and dismounting the vehicle. For instance, vehiclesmay include assist handles that may be deployed during mounting anddismounting of the vehicle, and then stowed during operation. Yet otherembodiments may provide a step-through chassis that provides low-stepheight access when mounting and dismounting the vehicle.

FIG. 1 illustrates an exemplary grounds maintenance vehicle 100 thatincorporates a suspension system 200 (see FIG. 2 ) in accordance withembodiments of the present disclosure. As stated above, the suspensionsystem 200 may operatively connect a chassis 102 of the vehicle with anoperator support platform 103. As a result, the support platform 103 may“float” relative to the chassis 102 via compliance of the suspensionsystem 200. That is, the suspension system 200 may allow for relativemotion between the support platform 103 and the chassis 102.

While the vehicle is shown and described herein as a self-propelledride-on lawn mower (also referred to herein simply as a “mower” or“vehicle”), such a configuration is not limiting. That is, those ofskill in the art will realize that embodiments of the present disclosuremay find application to other types of ride-on (e.g., sit-on orstand-on) grounds maintenance vehicles including skid-steer vehicles,aerators, material spreader/sprayers, dethatchers, snow throwers, anddebris management systems, to name a few.

As shown in FIG. 1 , the mower 100/chassis 102 may define front and rearends 125, 126, respectively, with a longitudinal or travel axis 101extending between the front and rear ends (i.e., the longitudinal axisbeing the axis of mower travel when the mower is traveling in a straightline). As used herein, a transverse axis or plane is any laterallyextending axis or plane that is normal to the longitudinal axis 101.

The chassis 102 may support a prime mover (e.g., internal combustionengine 104), which may, in one embodiment, be located at or near therear end 126 of the mower 100. Left and right ground-engaging drivemembers (e.g., rear drive wheels 106 a, 106 b) may be coupled to leftand right sides, respectively, of the chassis 102. Each drive wheel maybe powered to rotate, relative to the chassis 102, about an axis suchthat simultaneous and equal rotation of the two drive wheels causes themower 100 to move parallel to (i.e., along) the longitudinal axis 101.In some embodiments, the mower 100 may be configured as a ZTR vehicle,wherein the drive wheels 106 are independently driven by the engine 104(e.g., via one or more hydraulic motors/pumps, hydrostatictransmissions, or the equivalent). While described herein as an internalcombustion engine 104, other embodiments could utilize other primemovers, e.g., an electrical motor, to power the drive wheels 106, orutilize separate prime movers for propulsion and for implement (cuttingdeck) power. Moreover, while illustrated as wheels 106, otherembodiments may utilize other drive members (e.g., tracks or the like)without departing from the scope of this disclosure.

The mower 100 may additionally include one or more, e.g., two, supportmembers or wheels 108 a, 108 b. In the illustrated embodiment, thesupport wheels 108 are caster wheels and are located forward of thedrive wheels 106 (e.g., during normal forward travel of the mower) andare thus referred to herein simply as “front” wheels. Together, thewheels 106 and 108 support the mower 100 in rolling engagement with theground surface 105. While described herein as utilizing two rear drivewheels and two front castering wheels, such a configuration is merelyexemplary. For example, other embodiments may use more or less wheels(e.g., a tri-wheel configuration), while still other embodiments mayprovide different drive wheel configurations (e.g., front-wheel drive orall-wheel drive) or different steering configurations (e.g., a vehiclewith conventional Ackermann-type steering).

The mower 100 may further include one or more controls, e.g., left andright drive control levers 110 a, 110 b. The drive control levers 110may be pivotally coupled to the mower 100 (e.g., to the chassis 102)such that the levers may independently pivot forwardly and rearwardly(e.g., about a transverse axis) under the control of an operator locatedat an operator station that, in one embodiment, is configured as anoperator seat 112. Via incremental pivoting, the drive control levers110 are operable to control the speed and direction of their respectivedrive wheels 106 (e.g., the left lever 110 a may control speed androtational direction of the left drive wheel 106 a, while the rightlever 110 b may control speed and rotational direction of the rightdrive wheel 106 b) via manipulation of the mower's drive system. Whileillustrated herein as incorporating separate drive control levers 110,other controls, e.g., single or multiple joysticks or joystick-typelevers, touchpads, steering wheels, foot pedals, etc. could also be usedto control one or both of mower speed and direction.

An implement, e.g., lawn mower cutting deck 114, may be mounted to thelower side of the chassis 102, e.g., generally between the rear drivewheels 106 and the front wheels 108. The cutting deck 114 may include ahousing forming a cutting chamber partially surrounding one or morerotatable cutting blades (not shown) as is known in the art. While shownas a mid- or belly-mount deck, other embodiments may position the deckin other locations, e.g., forward of the front wheels 108, aft of therear wheels 106, lateral to the chassis 102, etc.

During operation, power is selectively delivered (by the prime mover104) to the cutting deck 114 and the drive wheels 106, whereby thecutting blades rotate at a speed sufficient to sever grass and othervegetation as the deck passes over the ground surface 105. Typically,the cutting deck 114 has an operator-selectable height-of-cut system toallow deck height adjustment relative to the ground surface 105.

The mower 100 may also include one or more side shells or fenders 116located relatively close to the operator seat. The fenders 116 providenot only storage areas for the operator, but also cover a variety ofvehicle controls and components, such as the fuel tank. The mower 100may include a fender on both the left (fender 116 a) and right (fender116 b) side of the operator seat 112 as shown in FIG. 1 .

In some embodiments, the fenders are constructed of plastic (but couldbe made of metallic and other non-metallic materials). Each fender mayinclude several cutouts for storage of items. For example, a cup holdermay be provided on one or both of the fenders. As stated above, eachfender may also accommodate a variety of machine controls, such as thedrive control levers, engine throttle, ignition, PTO engagement, etc.

As illustrated in the partial view of FIG. 2 , a suspension system,e.g., suspension system 200, may be operatively connected between thechassis 102 and the support platform 103. In one embodiment, thesuspension system 200 includes, among other components, a firstsuspension apparatus 202 and, optionally, a second suspension apparatus204.

The first suspension apparatus 202 may be longitudinally positioned(i.e., positioned along the longitudinal axis 101) at or near a rear endof the support platform 103 (e.g., at or near the seat support portion),while the second suspension apparatus 204 may be longitudinallyspaced-apart from the apparatus 202 such that it is located more towardan intermediate or central portion of the support platform 103. Whilesuch placement may position the suspension apparatus 202, 204 near acenter of the unsprung mass of the support platform 103, othersuspension apparatus locations are also contemplated.

While the exact placement may vary, the seat 112 is generally locatedmid-ship on the chassis (forward of the engine 104). One or moreisolators (not shown) may be provided between the seat 112 and a seatframe 111, the latter attached to the support platform 103. Theisolator(s) may include elastomeric elements that absorbmultidirectional forces resulting from engine and/or mower operation.Once again, while shown as a seat 112, operator stations adapted tosupport a standing operator are also contemplated within the scope ofthis disclosure.

One turf vehicle suspension system that provides adjustable spring anddampening characteristics is described in U.S. Pat. No. 9,499,204 (the“'204 Patent”). Embodiments described in the '204 Patent utilize anoperator platform that is supported, relative to a chassis of thevehicle, by a first and second suspension apparatus. In someembodiments, the first suspension apparatus includes first and secondshock absorbers laterally offset from one another, wherein the first andsecond shock absorbers are pivotable in a vertical plane. Pivoting ofthe shock absorbers alters the characteristics of the suspension systemas explained in the '204 Patent.

While the suspension system 200 of the present disclosure has elementsin common with systems described in the '204 Patent (e.g., a chassis,platform, and suspension system with a centered, forward suspensionapparatus), the system 200 does not utilize multiple, pivoting rearshock absorbers. Instead, the first suspension apparatus 202 is, in someembodiments, formed by one or more compact-height suspension unitslocated primarily beneath the seat elevation. For instance, as shown inthe partial perspective views of FIGS. 3 and 4 , the suspensionapparatus 202 may include first and second biasing elements (e.g.,torsion springs 206) as described in more detail below. In someembodiments, the two torsion springs are spaced-apart from one anotherin a transverse direction.

Similar to the vehicles described in the '204 Patent, the supportplatform 103 has a long dimension that extends along the longitudinalaxis 101. In addition to a seat support portion 120 to which the seat112 may couple, the support platform 103 may further define a footsupport portion 122, and a connecting structure 124, the latter whichmay connect the seat support portion to the foot support portion. Asshown in FIG. 2 , the seat support portion 120 may form the rear end ofthe platform 103, while the foot support portion 122 may form the frontend.

The connecting structure 124 may be a separate component of the platform103 or, alternatively, part of one or both of the seat support portion120 and the foot support portion 122. In general, the connectingstructure 124 may be of most any configuration that connects the seatsupport portion 120 to the foot support portion 122 of the supportplatform 103. For instance, in the illustrated embodiment, the footsupport portion 122 is vertically spaced-apart from (e.g., below) theseat support portion 120 and, in at least one embodiment, the footsupport portion 122 and the seat support portion 120 are in generallyparallel planes. As a result, the connecting structure 124 may beoriented in a direction that is generally vertical, or at an inclinefrom vertical. Regardless of its exact orientation, the connectingstructure 124 may extend from a forward end of the seat support portion120 downwardly to a rear end of the foot support portion 122. Asdescribed and illustrated herein, the connecting structure 124, the seatsupport portion 120, and/or the foot support portion 124 may incorporatefeatures (e.g., cutouts or openings) to accommodate the secondsuspension apparatus 204 (see FIG. 2 ). While the support platform 103is shown herein as a unitary (e.g., cast or welded) structure, those ofskill in the art will realize that it could also be an assembly ofmultiple components that are rigidly connected (e.g., bolted, welded,clamped, pinned, etc.), or otherwise attached to one another.

Although shown as being vertically spaced-apart, the seat supportportion 120 and the foot support portion 122 may, in other embodiments,both be on the same plane (i.e., forming a generally flat supportplatform 103). In such a configuration, the connecting structure 124 isunderstood to be an intermediate portion of the support platform 103that lies between the seat support portion 120 and the foot supportportion 122.

In the illustrated embodiments, the suspension system 200 includes thefirst suspension apparatus 202 and the second suspension apparatus 204,each of which operatively supports the platform 103 relative to thechassis 102 (e.g., biases the support platform away from the chassis) asthe platform moves through its range of motion. For purposes of thisdescription, potential degrees of freedom of the platform 103/seat 112,relative to the chassis 102, may be described as occurring in relationto three mutually perpendicular axes as shown in FIG. 1 : thelongitudinal or fore-and-aft axis x; the transverse or side-to-side axisy; and the vertical axis z. In addition to potential translation alongeach of these three axes, the platform 103/seat 112 may also potentiallypivot, relative to the chassis 102, about the x (e.g., “roll”), y (e.g.,“pitch”), and z (e.g., “yaw”) axes.

With reference to FIGS. 3 and 4 , the second suspension apparatus may beconfigured as a coil-over shock absorber 204 that defines a frontconnection of the platform 103 to the chassis 102. As shown in theseviews, the shock absorber 204 may be pivotally connected to the chassis102 at a frame pivot 210 and to the platform 103 (only partially shownin FIG. 4 ) at a platform pivot 212. The pivots 210, 212 may definetransverse, parallel axes 211, 213, respectively, about which the shockabsorber 204 may pivot. Moreover, the shock absorber 204 may utilizespherical rod ends at each of the pivots 210, 212 to allow limitedside-to-side translation of the platform 103 relative to the chassis102. While shown herein as a linear shock absorber, the secondsuspension apparatus could be configured as most any suspension deviceincluding, for example, one or more elastomeric elements, torsionsprings, extension springs, compression springs, gas-filled devices,etc. In fact, any device that is capable of providing elastic deflectioncould be used.

The suspension system 200 may further include a pivot member 250 thatdefines a rear connection of the platform 103 to the chassis 102. Thepivot member 250 may assist in reducing or even eliminating fore-and-aftand transverse (side-to-side) translation, as well as rolling andyawing, of the support platform 103 relative to the chassis 102. Inother words, the pivot member 250 may be configured to permit thesupport platform 103 to move generally up and down and pitch, whilereducing or eliminating transverse and fore-and-aft translation, as wellas rolling and yawing.

The pivot member 250 may define two transverse pivot axes: a first pivotaxis 252 and a second pivot axis 254. The pivot member 250 may bepivotally coupled to the chassis 102 at the first pivot axis 252, andpivotally coupled to the support platform 103 at the second pivot axis254. In the illustrated embodiment, the first and second pivot axes 252,254 are parallel to one another and transverse to the longitudinal axis101. The second pivot axis 254 may pivotally couple to the supportplatform 103 along the seat support portion 120 as shown (e.g., underthe center of mass of the operator). Moreover, while illustrated withthe first pivot axis 252 being located aft of the second pivot axis 254,other embodiments may place the first pivot axis forward of the secondpivot axis.

As shown in FIG. 3 , the pivot member may include transverse lugs 258(258 a, 258 b) that define the first pivot axis 252. Extending outwardly(forwardly) from the lugs 258 is at least one arm 260. In theillustrated embodiments, the pivot member 250 includes two such arms 260a, 260 b one extending from each of the lugs 258. Forward or oppositeends of the arms 260 define coaxial features (e.g., openings, pins,etc.) that permit pivotal connection to the platform 103 at the secondpivot axis 254.

FIG. 5 illustrates a portion of the suspension system 200 with variousvehicle structure removed to better illustrate the biasing elements ofthe first suspension apparatus 202, e.g., the torsion springs 206, oneof which is illustrated in isolation in FIG. 6 . Each torsion springincludes a coiled body 209 and protruding legs 207 and 208. The legs207, 208 may be generally equal in length, or may be different as shownin FIG. 6 , e.g., leg 208 may be longer that leg 207. The torsionsprings are adapted to elastically deflect when the support platform 103is displaced relative to the chassis 102.

The torsion springs 206 are positioned about a shaft 256 (via asupporting mandrel 257) extending along the second pivot axis 254 suchthat the coiled body 209 of each torsion spring moves with the secondpivot axis 254 during operation. A guide plate 262 is also pivotallyattached to the shaft 256 such that it may move with the second pivotaxis 254, as well as pivot about the second pivot axis 254.

FIG. 7 illustrates a section view taken along line 7-7 of FIG. 5 . Asindicated in this view, the coiled body 209 of each torsion spring 206is secured in place along the pivot axis 254. The leg 208 may then beardirectly against (abut) a load surface of either the guide plate 262 asshown (see also isolated perspective view of FIG. 8 ) or against a shaft288 (described below) associated with the guide plate, while the leg 207bears against (abuts) a receiver 264 formed along an inner face of theadjacent arm 260. Thus, the torsion springs 206 may directly act betweenthe shaft 288/guide plate 262 and the pivot member 250, and indirectlybetween the chassis 102 and the platform 103.

With reference to FIGS. 8 and 9 , the suspension system 200 may furtherinclude an adjustment mechanism or “adjuster” that permits a preload onthe torsion springs 206 to be altered, thereby changing suspensionsystem characteristics to best satisfy the preferences of a particularoperator. In some embodiments, the adjuster may include a Bowden cable266 having a first end 268 connected to a pulley (also referred toherein as a “cam”) of an adjustment lever 270 (see also FIG. 1 ), and asecond end 272 connected to the guide plate 262 or the shaft 288 asfurther described below. Such an adjuster may permit the action requiredto alter the preload (e.g., lever movement) to occur remotely from thetorsion springs. That is to say, the lever 270 may be located at almostany location on the mower 100, regardless of proximity to the supportplatform.

The pulley is attached to an adjustment lever 270 that is pivotable,relative to the chassis 102 about an eccentric pivot axis 274, between aplurality of discrete positions. The pulley defines a cam surface 276along which an inner member 278 of the cable 266 may wrap as thelever/pulley is moved through its range of pivotal motion (full rangerepresented by position “A” (corresponding to highest torsion springpreload) and position “B” (corresponding to lowest preload) in FIG. 9 ).An outer housing 280 of the cable 266 may then have one end anchored tothe chassis 102 as shown in FIG. 9 , and its opposite end anchored to abracket 107 connected to the platform 103 as shown in FIG. 7 . As thelever 270 moves from position B toward position A in FIG. 9 , the innermember 278 may slide within the outer housing 280, displacing the shaft288, and thus the guide plate 262, from the position shown in FIG. 7 ,to the position shown in FIG. 10 . As the shaft 288/guide plate 262 isdisplaced in this direction, the legs 208 of the torsion springs 206(which are in operative contact with the shaft 288) are displaced,effectively twisting the coiled body 209, which in turn increases thepreload simultaneously (and generally equally) on each of the torsionsprings. Similarly, the preload on the torsion springs may besimultaneously reduced by moving the lever 270 from position A backtoward position B.

To secure the guide plate 262 and shaft 288 at any one of multiple,discrete positions corresponding to positions A, B, and positions of thelever 270 therebetween, the lever may engage one of several discretenotches 282 as shown in FIG. 9 . That is, the lever 270 may be movedalong a slot 283 and, upon reaching the desired position, movedlaterally into engagement with the appropriate notch 282. As shown inFIG. 1 , each of the notches may include indicia (e.g., letters ornumbers) that indicate a relative preload of the springs (e.g., arelative stiffness of the suspension system). Such indicia may indicaterelative stiffness settings (for example, lever position B may beidentified as stiffness setting “1,” while lever position A may beidentified as stiffness setting “5,” wherein the intermediate notches282 may be identified as stiffness settings 2-4).

The profile of the cam surface 276 may be designed so that a relativelyconsistent actuation force moves the lever 270 through its range oftravel. That is to say, the cam surface 276 provides increasingmechanical advantage as lever resistance (i.e., torsion spring preload)increases. To ensure that the change in deflection of the torsionsprings 206 is generally equal between any two adjacent notches 282(thus providing generally linear preload variation between stiffnesssettings), the angular distance between one pair of adjacent notches maydiffer from a spacing between another pair of adjacent notches as isevident in FIG. 11 . For example, the lever 270 may pivot (about thetransverse pivot axis 274 of FIG. 9 ) through a greater angular travelas it moves between settings 4 and 5 than it does when pivoting betweensettings 1 and 2.

As shown in FIG. 9 , a lever spring 284 (tension spring) may be providedto bias the lever 270 and/or assist with moving the lever toward thehigher preload positions. While the particular parameters (length,spring rate, attachment point (moment arm) on pulley, etc.) of thespring 284 may vary, the spring may, in one embodiment, be selected toprovide lesser biasing torque to the lever (about the pivot axis 274) asthe lever 270 is moved toward positions corresponding to higher torsionspring 206 preloads, and greater biasing force as the lever is movedtoward positions corresponding to lower torsion spring preloads. In someembodiments, the spring 284 may be selected to provide a biasing torqueon the lever that is approximately equal and opposite to the torqueapplied by the torsion springs 206 (via the cable 266) when the lever270 is in an intermediate position (e.g., setting 3 as shown in FIG. 11). As the handle 270 moves from the intermediate position toward aposition corresponding to a higher preload on the torsion springs 206(e.g., toward a preload setting that is higher than the intermediatesetting such as setting 5 in FIG. 11 ), the biasing torque provided bythe spring 284 decreases. However, as the handle 270 moves from theintermediate position toward a position corresponding to a lower preloadon the torsion springs (e.g., toward a preload setting that is lowerthan the intermediate setting such as setting 1 in FIG. 11 ), thebiasing torque provided by the spring 284 increases. As a result, theassist spring 284 may, along with the cam surface 276, assist withmaintaining a more consistent lever actuation force regardless of thelever's position along the slot 283.

FIG. 8 illustrates attachment of the cable 266, e.g., the inner member278, to the shaft 288/guide plate 262. In this embodiment, the plate mayinclude an opening 285 through which a cable eye 286 (attached to secondend 272 of the inner member 278) may pass. The eye 286 may include anaperture adapted to receive the shaft 288 that is itself engaged withthe guide plate by passing through openings 289 formed on the top of theguide plate. The opening 285 allows pivoting of the eye 286 about theshaft 288 as the shaft 288/guide plate 262 moves through its range ofmotion (see, e.g., FIGS. 7 and 10 ). As one can appreciate, the guideplate 262 may be used merely to stabilize the shaft 288. That is to say,the adjustment mechanism (i.e., the cable 278) may not even require theguide plate 262. However, use of the guide plate 268 may ensure that theshaft 288 does not shift out of place during operation.

The illustrated construction allows the preload on the torsion springs206 to be simultaneously (and generally equally) adjusted by manuallymoving the lever 270 between different notches 282 in the slot 283 ofthe chassis 102 (see FIG. 9 ). As the lever moves, the cable 266 causesthe shaft 288/guide plate 262 to pivot about the second pivot axis 254,effectively increasing or decreasing the preload on the torsion springs206. Although not acting directly between the platform 103 and thechassis 102, the torsion springs 206 may resist pivoting of the pivotmember 250 about the first pivot axis 252, effectively biasing theplatform relative to the chassis.

To limit travel of the support platform 103 relative to the chassis 102,stops 290 and 292 may be provided as shown in FIG. 10 . The stop 290(one located under each arm 260 a, 260 b) may limit downward movement ofthe platform 103 by contacting the arms 260 of the pivot member 250,while the stop 292 (attached to the bracket 107) may limit upwardmovement of the platform upon contact with the pivot member. In theillustrated embodiments, the stops 290, 292 are formed of a resilient,compressible material such as rubber (e.g., neoprene) to effectivelyreduce hard, jarring impacts at the travel extremes of the platform 103.

FIGS. 11-14 illustrate an adjustment mechanism 271 in accordance withanother embodiment of the present disclosure. The adjustment mechanismillustrated in FIGS. 11-14 is similar in many respects to the thatdescribed above and thus like reference numerals are used whereappropriate. For instance, the adjustment mechanism again includes thelever 270 movable along the slot 283 and, upon reaching the desiredposition, is movable laterally into engagement with the appropriatenotch 282. However, while the adjustment mechanism described previouslyrequired only a single step procedure (moving the lever from one notchto another), the adjustment mechanism 271 requires a two-step procedurein order to change the torsion spring preload.

For example, in one embodiment, the adjustment mechanism may include alever lock 273 as shown in FIGS. 11 and 12 . When the lever lock 273 isin a first or closed position (see FIG. 13 ), the lever lock physicallyobstructs movement of the lever 270 out of the notches 282 and into theslot 283. That is to say, the lever lock 273 may “lock” the lever 270 inany one of the available notches 282.

While various lever lock configurations are contemplated, an exemplaryconstruction is illustrated in FIGS. 11-13 (lever lock shown in thefirst or closed position in these figures). As indicated in these views,the lever lock 273 may be configured as a shaft 275 journalled forrotation about an axis 277 that extends generally parallel to the slot283. The shaft 275 may further define a radially extending protrusion orear that forms the lever lock 273.

The back end of the shaft 275 may have attached thereto a handle or knob279 wherein rotation of the knob results in rotation of the shaft and,therefore, pivoting of the lever lock 273. The shaft 275 may furtherinclude a leg 281 as shown in FIG. 12 for attachment of a spring orother biasing element (not shown) adapted to bias the lever lock 273 tothe first or closed position as shown in FIGS. 11-12 .

FIG. 13 is a section view taken along line 13-13 of FIG. 11 . As shownin this view, the lever lock 273, which is illustrated in the first orclosed position, may again effectively obstruct or block movement of thelever 270 from the notch 282 into the slot 283.

When the operator wishes to adjust the position of the lever 270 (tochange a preload on the torsion springs), he or she dismounts the mower(if already seated) and, standing to the side of the mower, rotates theknob 279 in the direction 269 (see FIG. 11 ) with a first (e.g., left)hand. Such rotation of the knob 279 causes the shaft 275, and thus thelever lock 273, to move from the first or closed position shown in FIG.13 , to a second or open position shown in FIG. 14 . In the openposition, the lever 270 is free to move, under a displacing forceprovided by the operator's other (e.g., right) hand, from the notch 282into the slot 283 (in the direction 267), at which point the lever ismoved until it aligns with another one of the notches. Once the lever270 is placed into the newly-selected notch 282, the knob 279 isreleased, allowing the bias applied to the shaft 275/lever lock 273 (ina direction opposite the direction 269 in FIG. 13 ) to return the leverlock to the closed position (see FIG. 13 ), thereby locking the lever270 in the newly-selected notch.

The adjustment mechanism 271 thus requires the operator to execute twodiscrete steps (while dismounted from the mower) in order to adjust thetorsion spring preload. First, the knob 279 is rotated with one hand tomove the lever lock 273 out of the closed position (see FIG. 13 ) andinto the open position (see FIG. 14 ). While holding the knob 279 withone hand to maintain the open position of the lever lock, the operator,using his or her other hand, moves the lever 270 in the direction 267(see FIG. 14 ) to relocate the lever to a different notch 282. At thispoint, the knob 279 is released, thereby locking the lever 270 in thisnewly-selected notch 282.

FIGS. 15-20 illustrate a suspension system 300 in accordance with analternative embodiment of the present disclosure. As is evident below,the system 300 is similar in many respects to the system 200 describedabove. For example, the system 300 may again include the secondsuspension apparatus 204 (not shown) and a first suspension apparatusincluding two torsion springs 306 positioned beneath the platform 103.However, unlike the system 200, the suspension system 300 may use anadjustment mechanism (adjuster) formed by a rotatable threaded adjusteror screw 370, which may be located under and/or to the rear of the seat(see seat 112 in FIG. 1 ). FIG. 16 is a view similar to FIG. 15 , buttaken from a rear perspective.

A preload on the torsion springs 306 may be adjusted via rotation of thescrew 370. For example, rotation of the screw 370 in a clockwisedirection simultaneously tightens (i.e., increases the preload of) thetorsion springs 306, which thereby increases the stiffness of thesuspension system. Similarly, rotation of the screw 370 in acounterclockwise direction loosens (i.e., decreases the preload of) thetorsion springs, thereby decreasing the stiffness of the suspensionsystem. The system 300 may also include a transverse retention bar 392to limit an upward position of the platform 103.

In some embodiments, an indicator, e.g., vertical tab 372, is provided.As the screw 370 is rotated, the tab 372 may rise or fall, relative to aslot 373 in the platform, in proportion to the preload applied to thetorsion springs 306. The tab 372 may include various indicia (paralleland horizontal letters, numbers, pictures, etc.) that correspond tovarious preload settings. As a result, the position of the tab 372, withthe corresponding indicia, enables the operator to gauge the degree ofpreload (stiffness) of the suspension system. While shown as a lineartranslating tab, the indicator could also be configured as a dial gauge,wherein a needle of the gauge would move as the screw 370 is rotated.

FIG. 17 is a section view of the vehicle suspension system 300 takenalong line 17-17 of FIG. 16 . In this view, the suspension system isshown: adjusted to the lightest preload (least-stiff) setting; and in anuncompressed or unloaded state. FIG. 18 is a perspective view of thissame section from a rear perspective. The transverse retention bar 392is also visible in these views. The bar 392 may abut an elastomeric pad393 operatively attached to the platform to effectively limit an upwardposition of the platform.

As shown in these views, the mower 100 incorporating the suspensionsystem 300 may again include a frame or chassis 102, operator supportplatform 103, suspensions apparatus 204 (not shown), pivot member 350(pivotally attached to the chassis 102 at a first transverse pivot axis352, and to the support platform at a second transverse pivot 354), andtorsion springs 306 that are configured as generally described herein inthe context of the mower 100/suspension system 200. The torsion springs306 may be similar or identical to the springs 206 already describedherein, e.g., include in inner leg 307 that engages a receiver 364(protruding stud) on the pivot member 350, while the outer leg 308engages an adjustment pad 368 that is vertically displaceable by thescrew 370.

During operation, the torsion springs 306, like the springs 206, mayattenuate operating loads that may otherwise be transmitted to theplatform 103. For instance, FIG. 19 is a view similar to FIG. 17 , butwith the suspension system in a fully compressed or fully loaded state.Similarly, FIG. 20 is a view similar to FIG. 17 (in the unloaded state),but with the adjuster configured to provide the suspension system 300with a higher preload on the springs 306 (higher suspension systemstiffness). That is, the screw 370 has been rotated to displace the pad368 downwardly to deflect the leg 308 and effectively preload bothsprings 306.

While illustrated herein as using either a pivoting guide plate/cable ora screw to form the adjuster, other embodiments are contemplated. Infact, most any device operable to apply a preload to the torsion springs(e.g., a lever, direct acting cam, etc.) is possible within the scope ofthis disclosure.

While shown as utilizing torsion springs to form the first suspensionapparatus, other embodiments may utilize other suspension units alsocontained generally beneath the support platform 103 without departingfrom the scope of this disclosure. For example, FIGS. 21-22 illustrate amower 100 (only partially shown) that incorporates a suspension system400 in accordance with another embodiment of this disclosure. As isindicated below, the system 400 is similar in many respects to thesystems 200 and 300 described above. For example, as shown in FIG. 21 ,the system 400 may again include a frame or chassis 102, operatorsupport platform 103, suspension apparatus 204, and pivot member 450configured as generally described herein with the same or similarlycorresponding reference numerals in the context of the mower100/suspension system 200. The pivot member 450 may again pivotallyattached to the chassis 102 at a first transverse pivot axis 452, and tothe support platform at a second transverse pivot 454. However, unlikethe suspension systems 200 and 300, the suspension system 300 replacesthe torsion springs 206, 306 with a suspension apparatus 402 thatincludes one or more coil-over shock absorbers 406 positioned in ahorizontal or approximately horizontal orientation as shown.

With reference to FIG. 22 , the motion of the platform 103 relative tothe chassis is again defined by the suspension apparatus 204 (e.g., thepivot member 450). However, the suspension apparatus 400 also includes abell-crank or pivot plate 416 that is fixed to a pivot shaft 418 suchthat the pivot plate may pivot, relative to the chassis 102, about atransverse pivot axis 420. The shock absorber 406 may have a first endpivotally coupled to the chassis at a frame pivot 422, and a second endpivotally coupled to the pivot plate at a shock pivot 424. The framepivot 422 and the shock pivot 424 may both allow pivoting of the shockabsorber about associated transverse pivot axes.

The suspension system 400 may further include an arm 426 having a firstend pivotally connected to the platform 103 at a platform pivot 428, anda second end defining a stub shaft 430 adapted to pivotally engage thepivot plate 416. In some embodiments, the pivot plate 416 may define aslot 432 with two or more notches 434 in communication therewith.

During operation, the platform 103 may move, relative to the chassis102, via compliance of the suspension apparatus 204 and movement of thepivot member 450 as already described herein with respect to thesuspension systems 200 and 300. As the rear of the platform 103 isdisplaced downwardly during operation, the arm 426 may transfer downwardforces to the pivot plate 416, causing the pivot plate to pivot aboutthe transverse pivot axis 420 defined by the pivot shaft 418 in thedirection 436. This pivoting of the pivot plate 416 is resisted by theshock absorber 406, which provides a biasing force to the pivot plate ina direction opposite the direction 436. As a result, downward motion ofthe platform 103 is influenced (resisted) by the suspension apparatus204 and the shock absorber 406.

As with the systems 200 and 300 described herein, the suspension system400 may permit adjustment of the preload on the shock absorber 406 topermit altering suspension system characteristics. For example, in someembodiments, the stub shaft 430 may be moved to a different notch 434.Such movement alters the distance between the pivot axis 418 and theforce vector applied by the arm 426, effectively increasing (ordecreasing) the moment about the pivot axis resulting from loading ofthe platform 103. In addition or alternatively to moving the stub shaft430 to a different notch, the pivot plate 416 may include multiple,e.g., three, apertures 438, each of which is spaced at a differentdistance from the pivot axis 418. Accordingly, the shock pivot 424 maybe located at correspondingly different distances from the pivot axis418, which may also alter the effective resistance or preload applied bythe shock absorber 406. The notches 434 and/or apertures 438 may alsoinclude indicia that may assist the operator in adjusting the preload onthe shock absorber.

Adjustable positioning of the shock pivot 424 and/or the stub shaft 430on the pivot plate 416 may allow significant range of resistanceprovided by the shock absorber 406. As a result, adequate suspensionvariability may be achieved using only a single shock absorber 406 (inaddition to the front shock absorber 204). Such a construction mayreduce system cost and complexity for some applications.

Moreover, the shock absorber 406 of the system 400 integrates a dampener(gas strut) therein, which may be beneficial in some instances, e.g.,where dampening is desired. However, those of skill in the art willrecognize that the torsion spring concepts described herein could also,if desired, incorporate a dampening element (in addition to the dampenerprovided in front shock absorber 204) to control platform rebound motionwithout departing from the scope of this disclosure.

Suspension systems described herein thus allow for a compact vehiclesuspension system that may be adjusted to provide the desired suspensioncharacteristics. Moreover, exemplary suspension systems may include anadjustment mechanism that allows a preload on one or more biasingelements (e.g., on both torsion springs, or on the shock absorber 406)to be altered. In some embodiments, the first suspension apparatus mayinclude two suspension units (torsion springs 206) and the adjustmentmechanism may be adapted to adjust preload on both units simultaneously.

In addition to suspension systems, embodiments of the present disclosuremay provide features that assist with mounting and dismounting theoperator platform 103 (e.g., the seat 112). For example, FIGS. 23-24illustrate an assist bar 500 attached, directly or indirectly, to themower chassis 102 of the mower 100. While not wishing to be bound to anyspecific configuration, the assist bar 500 may extend upwardly from neara floor pan (e.g., foot support portion 122 of the platform 103). Theassist bar 500 may be positioned within easy reach as the operator isrising from the seat 112, or as he/she is otherwise mounting ordismounting the mower. The upper end of the assist bar may include ahandle portion 502, which may have a soft, ergonomically-shaped surfacethat is comfortable to grip.

A lower end of the assist bar may be pivotally connected to the chassis102 by any suitable means. For instance, in some embodiments, a mount orbracket 504 may be attached to a frame rail 109 of the frame 102 at alocation in front of, and to the side of, the operator seat 112. Thebracket 504 may include a slot 506 while the assist bar 500 includespins 508, 510 that may move within the slot(s) to allow pivotal movementthe assist bar between a collapsed or stowed position “B” and a raisedor deployed position “A.”

The assist bar 500 is shown in both the deployed position A and thecollapsed position B in FIG. 23 (such depiction is for illustrationpurposes only as the bar would be in either position A or position B (orsome intermediate position) at any given time). The pivotal connectionof the assist bar 500 to the chassis 102, as further described below,may allow the assist bar to selectively lock or otherwise be secured inthe deployed position A. With the assist bar in the deployed position,the operator may grasp the handle portion 502 duringmounting/dismounting of the mower. That is to say, the assist bar 500may provide an additional support to assist the operator as he/shemounts and dismounts the mower.

As stated above, the assist bar 500 may be designed to pivot to thestowed position B as shown in FIG. 23 . In the stowed position, theassist bar is generally positioned to minimize interference with machinesteering controls and operator line-of-sight. Moreover, stowing theassist bar 500 may reduce inadvertent contact of the assist bar withsurrounding bushes, trees, or other obstacles during use of the mower.In one embodiment, the assist handle 502 is located at or near the seat112 when in the stowed position to allow convenient access duringmovement of the assist bar toward or away from the stowed position B.

As shown in FIG. 24 , pivotal attachment of the assist bar may beaccommodated by the bracket 504. The bracket includes the slot 506having a vertical portion 512 rising to intersect with an arc-shapedportion 514. As stated above, the assist bar 500 may include the twopins 508 and 510 that move within the slot 506. Specifically, when theassist bar 500 is in the deployed position A as shown in solid lines inFIG. 24 , the two pins 508, 510 are captured within the vertical portion512 of the slot 506 such that the assist bar is held in place (againstall but vertical displacement). When the operator wishes to move theassist bar 500 to the stowed position B shown in broken lines in FIG. 24, the assist bar 500 may be displaced upwardly (e.g., in the direction516) until the upper pin 508 exits the vertical portion 512 of the slot506 and enters the arc-shaped portion 514. At this point, the bar 500may be pivoted about the lower pin 510 in the direction 518 as the upperpin 508 moves along the arc-shaped portion until the assist bar reachesthe stowed position B. Accordingly, the positions of the pins 508 and510 may be located in the positions indicated as “A” when the assist bar500 is in the deployed position A, and in the positions indicated as “B”when the assist bar is in the stowed position B.

In another embodiment, the assist bar extends above the foot plate in asubstantially vertical orientation, and its upper end again includes ahandle portion. However, instead of moving to a stowed position viapivotal movement, this alternative assist bar may have a telescopingconstruction to collapse its height when not in use. Such a telescopingassist bar is described in more detail in U.S. Pat. No. 8,794,660.

In other embodiments, other features may be provided to assist theoperator with mounting and dismounting the mower. For example, FIGS.25-26 illustrate a ZTR mower 600 having a fixed foot support portion orfloor pan 603 as opposed to the floating platform 103 describedelsewhere herein.

The ZTR mower 600 includes a pair of caster wheels 608 at the front ofthe mower. In conventional ZTRs, the two front caster wheels areinterconnected by a straight axle or “beam.” In order to accommodate thecaster wheel diameter and the caster mechanism, this beam may be locatedat an elevation that creates a step-up height higher than what someoperators may prefer when stepping onto, or off of, the mower. Moreover,in conventional ZTRs, an angled foot rest is commonly included andgenerally extends across the transverse width of the front of the mower.As a result, when mounting/dismounting such mowers from the front, theoperator may be required to step not only to the height defined by thebeam, but also sufficiently high to traverse the foot rest.

Mowers in accordance with embodiments of the present disclosure,however, may utilize a beam 616 that is, at least near a centerline ofthe mower 600, at a lower elevation (e.g., at an elevation that is about1.5-2 inches lower) than its elevation near the caster wheel mounts 624.In fact, as shown in FIG. 25 , the beam 616 may be at the sameelevation, e.g., flush with, the floor pan 603.

Moreover, the mower 600 may further include a step-through foot rest618, which allows the operator to step on and off the machine easily viathe mower's front end without obstruction from the foot rest. Thisfeature, in combination with the front beam 616 being generally flush inelevation with the floor pan, provides a single, unobstructed step thatis positioned more closely to the ground than may otherwise be possiblewith a conventional beam and footrest configuration.

To provide this step-through path, the front of the mower uses twospaced-apart transverse foot rest members 618 a, 618 b (as opposed to asingle continuous foot rest) secured to the front portion of the floorpan 603. Each foot rest member is generally V- or U-shaped and presentsan angled surface upon which the operator may rest his or her feet whensitting in the seat 612. Each of the foot rest members 618 a, 618 bextends in a transverse direction near the front of the floor pan 603.The step-through feature is then formed between the spaced-apart footrest members 618.

The step-through area may be configured to provide surfaces thatminimize slipping and falls. Specifically, the surfaces of the foot restmembers and step-through areas may have either an adhesive-backedtextured decal, or may be stamped or embossed. Such surfaces mayincrease the operator's traction when mounting or dismounting the mower.

FIG. 26 depicts the chassis 602 with various structure removed toillustrate the shape of the transverse beam 616. As shown in this view,the transverse beam 616 may include a flat center portion 620 near itscenter, and upwardly and outwardly extending portions 622 extending fromthe flat center portion transversely to the caster wheel mounts 624.Stated another way, the beam 616 may appear as a flattened “V” shapewhen viewed from the front of the mower.

Operator mount/dismount access features (e.g., assist bar, step-throughfront) as described herein may find application to mowers with orwithout suspension systems. In fact, such features may be utilized withother non-mowing vehicles without departing from the scope of thisdisclosure.

The complete disclosure of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. In the event thatany inconsistency exists between the disclosure of the presentapplication and the disclosure(s) of any document incorporated herein byreference, the disclosure of the present application shall govern.

Illustrative embodiments are described and reference has been made topossible variations of the same. These and other variations,combinations, and modifications will be apparent to those skilled in theart, and it should be understood that the claims are not limited to theillustrative embodiments set forth herein.

What is claimed is:
 1. A grounds maintenance vehicle comprising: achassis extending between a front end and a rear end along alongitudinal axis, the chassis comprising a beam extending across thefront end, the beam defining a top surface and comprising: a firstportion having the top surface at a first elevation, a second portionhaving the top surface at the first elevation, and a center portionbetween the first and second portions, the center portion having the topsurface at a second elevation lower than the first elevation relative toa ground surface when the vehicle is in an operating position; a firstfoot rest proximate the first portion of the beam; and a second footrest transversely spaced-apart from the first foot rest and proximatethe second portion of the beam.
 2. The grounds maintenance vehicle ofclaim 1, wherein the first foot rest is disposed above the beam and thesecond foot rest is disposed above the beam.
 3. The grounds maintenancevehicle of claim 1, wherein the second elevation is about 1.5 to 2inches lower than the first elevation.
 4. The grounds maintenancevehicle of claim 1, wherein the first portion of the beam extendsupwardly and transversely outwardly from the center portion of the beam,and wherein the second portion of the beam extends upwardly andtransversely outwardly from the center portion of the beam.
 5. Thegrounds maintenance vehicle of claim 1, wherein the first foot rest andthe second foot rest are transversely spaced apart by a distance aboutequal to a length of the center portion of the beam.
 6. The groundsmaintenance vehicle of claim 1, further comprising a support platformextending along the longitudinal axis between a left side of the chassisand a right side of the chassis.
 7. The grounds maintenance vehicle ofclaim 1, further comprising a first wheel mount at a first end of thefirst portion of the beam and a second wheel mount at a second end ofthe second portion of the beam.
 8. The grounds maintenance vehicle ofclaim 1, further comprising an assist bar connected to the chassis, theassist bar positioned to be reachable by a user mounting or dismountingthe vehicle.
 9. A grounds maintenance vehicle comprising: a chassisextending between a front end and a rear end along a longitudinal axis,the chassis comprising a beam proximate the front end, wherein the beamextends between a left side and a right side of the chassis, wherein thebeam comprises a first end proximate the left side of the chassis, asecond end proximate the right side of the chassis, and a center portionbetween the first end and the second end, the center portion comprisingan upper surface; a support platform extending along the longitudinalaxis between the left and right sides of the chassis, wherein thesupport platform contacts the upper surface of the center portion of thebeam; a first foot rest proximate the first end of the beam; and asecond foot rest transversely spaced-apart from the first foot rest andproximate the second end of the beam.
 10. The grounds maintenancevehicle of claim 9, wherein the support platform comprises a seatsupport portion and a foot support portion, wherein the foot supportportion of the support platform contacts the upper surface of the centerportion of the beam.
 11. The grounds maintenance vehicle of claim 9,wherein the first foot rest is disposed above the beam and the secondfoot rest is disposed above the beam.
 12. The grounds maintenancevehicle of claim 9, wherein a first portion of the beam extends upwardlyand transversely outwardly from the center portion of the beam andtowards the first end, and wherein a second portion of the beam extendsupwardly and transversely outwardly from the center portion of the beamand towards the second end.
 13. The grounds maintenance vehicle of claim9, wherein the first foot rest and the second foot rest are transverselyspaced apart by a distance about equal to a length of the center portionof the beam.
 14. The grounds maintenance vehicle of claim 9, furthercomprising a first wheel mount at the first end of the beam and a secondwheel mount at the second end of the beam.
 15. A grounds maintenancevehicle comprising: a chassis comprising a left side support bar and aright side support bar, wherein the left and right side support barsextend between a front end and rear end generally parallel along alongitudinal axis, the chassis comprising a beam proximate the frontend, the beam comprising: a first portion proximate the left sidesupport bar, wherein an upper surface of the left side support bar ispositioned higher than the first portion at an area of intersectionbetween the left side support bar and the beam, a second portionproximate the right side support bar, wherein an upper surface of theright side support bar is positioned higher than the second portion atan area of intersection between the right side support bar and the beam,and a center portion between the first and second portions; a first footrest proximate the first portion of the beam; and a second foot resttransversely spaced-apart from the first foot rest and proximate thesecond portion of the beam.
 16. The grounds maintenance vehicle of claim15, wherein the first foot rest is disposed above the beam and thesecond foot rest is disposed above the beam.
 17. The grounds maintenancevehicle of claim 15, wherein the first portion of the beam extendsupwardly and transversely outwardly from the center portion of the beam,and wherein the second portion of the beam extends upwardly andtransversely outwardly from the center portion of the beam.
 18. Thegrounds maintenance vehicle of claim 15, wherein the first foot rest andthe second foot rest are transversely spaced apart by a distance aboutequal to a length of the center portion of the beam.
 19. The groundsmaintenance vehicle of claim 15, further comprising a support platformextending along the longitudinal axis between the left and right sidesupport bars.
 20. The grounds maintenance vehicle of claim 15, furthercomprising a first wheel mount at a first end of the first portion ofthe beam and a second wheel mount at a second end of the second portionof the beam.